Crystal-lang no overload matches 'HTTP::Server.new' with type Int32 http server

Question

I'm a newbie to Crystal-lang.

I'm trying the Http Server example given in the crystal-lang docs.

require "http/server"

server = HTTP::Server.new(8080) do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world! The time is #{Time.now}"
end

puts "Listening on http://127.0.0.1:8080"
server.listen

When I run this code I'm getting the following error.

Error in httpserv.cr:3: no overload matches 'HTTP::Server.new' with type Int32
Overloads are:
 - HTTP::Server.new(handlers : Array(HTTP::Handler), &handler)
 - HTTP::Server.new(&handler)
 - HTTP::Server.new(handlers : Array(HTTP::Handler))
 - HTTP::Server.new(handler : HTTP::Handler | HTTP::Handler::Proc)

server = HTTP::Server.new(8080) do |context|

What I can gather from this is I need to specify some methods/functions for handling the HTTP requests, but I'm not getting how to do that.

What is the correct way to do that is my question?

Thanks in advance.

score 5 · Accepted Answer · answered Jun 25 '18 at 15:03

The HTTP::Server API has changed in the latest release Crystal 0.25.0. It's use is documented in the recent API docs (the 0.25.0 release docs have a slight error, but it's fixed on master).

As you can see from the error message, the signature of Server.new has changed. It now only accepts some form of handler. You already have that defined in your example in the do block. The constructor no longer accepts a port number, but you need to call #bind_tcp seperately.

Your example should now look like this:

require "http/server"

server = HTTP::Server.new do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world! The time is #{Time.now}"
end

address = server.bind_tcp 8080
puts "Listening on http://#{address}"
server.listen

Crystal-lang no overload matches 'HTTP::Server.new' with type Int32 http server

1 Answers1